Konica Minolta provides HF/HE processing called “hybrid processing” as a standard function, which is an upgraded version of conventional frequency processing using multiresolution decomposition. Conventional emphasis processing in CR focused on two points: correcting the image density of the difficult-to-see part and emphasizing image sharpness.

Purposes of Noise Suppression Processing

New Image Processing (HS Processing)

HS Processing is an image processing method that reduces intrinsic image noise. It is a hybrid processing technology developed to increase image graininess and optimize the balance between contrast and noise in the image at the same time. Decreasing the response of non-edge (noise) components after recognizing edge components in the “multi-resolution decomposition” process of hybrid processing improves image graininess. Now we will explain the details of suppressing noise to improve graininess.

Graininess Improvement Method

Hybrid processing (HE/HF processing) uses frequency processing with multi-resolution decomposition that is capable of emphasizing, depending on the degree of detail in a structure (frequency in an image), while HS processing improves graininess by selectively reducing fine noise in an image.

What is multi-resolution decomposition?

In concrete terms, subtracting a smoothed image from the original image as shown in Fig. 2 only generates an image of the edge. Edge images of different degrees of fineness can be obtained by subtraction while changing the smoothing degree at the same time. Eliminating edge images with different degrees of fineness is called multi-resolution decomposition. It is the most basic part of recent image processing in CR and used in various processes. Konica Minolta provides processing using this multi-resolution decomposition as “hybrid processing.”

Fig 2

X-ray pictures copying the human body consist of collective structures with different degrees of fineness, the image can become very clear by extracting the edge part of each fineness (multi-resolution) and adding or subtracting it from the original image as needed.

HS Processing Technology and Principle

The following three processes, known as image speckling, are added to the hybrid processing routine using multi-resolution decomposition, as explained in the previous section, to improve graininess.